// github.com/RodneyShag

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

class Animal {
    void walk() {
        System.out.println("I am walking");
    }
}

class Bird extends Animal {
    void fly() {
        System.out.println("I am flying");
    }
    void sing() {
        System.out.println("I am singing");
    }
}

public class Solution {
   public static void main(String args[]) {
      Bird bird = new Bird();
      bird.walk();
      bird.fly();
      bird.sing();
   }
}
